Conventionally, a filament winding device which winds a band-like fiber bundle around the outer periphery of a liner has been known. The filament winding device is provided with a creel stand, and a plurality of bobbins around which the fiber bundle is wound are arranged in the creel stand (for example, see Patent Literature 1). With regard to the filament winding device, the fiber bundle is unwound from each bobbin arranged in the creel stand in the form of rollingly reeling-off type, whereby the fiber bundle is wound around the outer periphery surface of the liner.
In the case of such filament winding device, especially in the case of a multiple yarn supply type filament winding device, the fiber bundles reeled off from the plurality of bobbins have to be guided and simultaneously wound onto the liner. Therefore, the creel stand tends to be increased in size. As such, the fiber bundles unwound from the bobbins tend to be increased in running distance, and the fiber bundles unwound from the bobbins need to be guided while being bent thereby being arranged in appropriate traveling directions. Accordingly, in the case where the fiber bundles are guided while being bent to different directions relative to the unwinding direction in which the fiber bundles are unwound from the bobbins, the fiber bundles may be turned upside down by the effect of twisting action. That is to say, there is a possibility of turnover of the fiber bundle.
Specifically, as shown in FIG. 5, a fiber bundle F unwound from a bobbin B is twisted between the bobbin B and a fixed guide 45. A twisting angle of the fiber bundle F fluctuates depending on the traversing of the fiber bundle F. At the position where the fiber bundle F is unwound from the bobbin B, one side in the width direction of the fiber bundle F is defined as a1, and the other side in the width direction of the fiber bundle F is defined as a2, whereas at the position where the fiber bundle F is whipped to the fixed guide 45, one side in the width direction of the fiber bundle F is defined as b1, and the other side in the width direction of the fiber bundle F is defined as b2. In that case, a difference between a distance from a1 to b1 and a distance from a2 to b2 becomes maximum at positions in the vicinity of folding-back positions TL, TR of traversing due to the traversing of the fiber bundle F. Accordingly, there is the case that the behavior of the fiber bundle F becomes unstable, and there is a problem in which a possibility of turnover of the fiber bundle F increases. As such, there is the threat that the fiber bundle F might be wound around the liner in a twisted state, and that might cause degradation of quality and deterioration of strength of a product.
Furthermore, the tension applied to the fiber bundle F fluctuates depending on the traversing of the fiber bundle F. That is to say, since the zone distance from the bobbin B to the fixed guide 45 varies depending on the traversing of the fiber bundle F, the tension applied to the fiber bundle F fluctuates. Accordingly, there is the case that the behavior of the fiber bundle F becomes unstable, and there is a problem in which the possibility of turnover of the fiber bundle F increases.